Process of producing aluminium and its alloys.



UNITED STATES Patented Ma 12, 1903'.

I ATENT Tries.

PROCESS OF PRODUCING ALUMIN IUM AND ITS ALLOYS.

SPECIFICATION forming part of Letters Patent No. 728,129, dated May 12, 1903. Application filed November 5 26, 1895. Serial No. 570,233. (specimens) To CLZZ whom it may concern:

Be it known that I, DMITRY ALEXANDRO- WITCH PENIAKOFF', a subject of the Emperor of Russia, and a resident of Huy, Belgium, have invented a new and Improved Process of Producing Aluminium and its Alloys from Aluminium Sulfids or Double Sulfids Thereof, of which the following is a full, clear, and exact description.

My invention relates to a process for producing aluminium and its alloys by treating a sulfid of aluminium (or a double sulfid of aluminium and some other metal) with various reducing gases or mixtures thereof.

With this object in view my invention consists in subjecting porous aluminium sulfid or a porous double sulfid of aluminium and another metal to the action of a reducing agent, such as hydrocarbon gas or vapors.

It also consists in the employment of a suitable fluX in connection therewith, the product resulting from the reduction being melted with such flux for collection and purification.

My invention, moreover, consists in such other features, steps, and methods as will be hereinafter set forth, and pointed out in the claims.

In carrying out my invention I start with a special form of sulfid of aluminium or double sulfid of aluminium and 'another metal prepared according to a process fully described in my Letters Patent of the United States, No. 606,576, dated June 28, 1898. 'By this process I obtain the sulfid in a new and very porous condition, such porosity having an important bearing on the success of the operation.

Sulfid of aluminium has generally been obtained by the laboratory methods of keeping alumina heated to a white heat in a vapor of bisulfid of carbon for several hours. The

product thus obtained is a black or gray moldrated sulfate ofaluminium (instead of dense alumina) and so conductthe process that the reaction between said dehydrated sulfate of aluminium and bisulfid of carbon proceeds at a relatively low temperature. The reaction begins when deep-red incandescence sets in, a considerable amount of latent heat being at the same time liberated, and owing to the latent heat being thus developed only a small amount of heat from the outside is needed. The product (sulfid of aluminium) obtained in this way is a light porous substance Whose pervious and absorbent character and large surface exposure renders it susoeptible of decomposition and practically reducible by hydrocarbon vapors. This aluminium sulfid, which owing to its porous structure is readily pervious togases, is treated with dry hot vapors or gases of the hydrocarbons contained in illuminating gas or other gaseous reducing agents. The product resulting from this treatment is a dark-brown or black body similar to coke containing finely-divided metallic aluminium, free carbon separated from the reducing-gases, and aluminium carbid. It may be considered as a compound of aluminium and carbon. This substance when melted with any suitable flux will yield pure metallic aluminium. This flux should be specifically lighter than the aluminium, readily melted, and sufficiently thin when melted. The flux which I employ is a mixture of the chlorids or fluorids of alkalies or alkaline earths. This melting of the cokelike product with a flux I consider indispensable, since the mere treatment of aluminium sulfid with reducing-gases has not yielded any practical resultsthat is to say, no appreciable or considerable amount of metallic aluminium is obtained where the treatment with a flux is omitted.

The object of the flux is to separate the carbon which is found to be chemically and mechanically associated with the aluminium after reduction. This carbon can only be separated by melting the mixed product with such flux.

By adding any other metal to the flux during or before the smelting operation an alloy of such metal and aluminium is obtained. Another method of producing alloys is to employ instead of aluminium sulfid a double sulfid of aluminium and the metal suitable for the purpose-such as copper, for examplewith which it is desired to alloy it.

As another reducing agent of remarkable energy I would mention a mixture of ammonia with gas from a Siemens generator, which mixture is particularly suitable for reducing aluminium sulfid (or a double aluminium sulfid) after having passed over incandescent carbon and, if necessary, through sulfuric acid.

If a mixture of ammonia-gas with Siemens regenerat-or gases is conducted over glowing carbon, cyanid of ammonia is produced. The reaction is expressed by the following equation:

If the cyanid so obtained be conducted through any acid, preferably sulfuric acid, free hydrocyauic acid remains as an ingredi ent of the gaseous mixture. This gaseous mixture, as stated, when absorbed by the porous aluminium sulfid or double sulfid of aluminium and other metal reduces the same to metallic aluminium or aluminium alloy.

The practical application of my improved method presents no difficulties, since the material to be reduced is exceedingly porous, and therefore readily pervious to the gases, so that a complete reduction is effected in .a comparatively short time.

I desire it to be understood that the original substance treated according to my hereinbefore-described process always is a porous sulfid of aluminium, either simple aluminium sulfid Ora double aluminium sulfid. The final product always is aluminium in a metallic state, either pure or alloyed with other metals.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. The herein-described process which consists in subjecting porous aluminium sulfid to the action of a reducing agent at a temperature suflicient to effect the reduction of aluminium.

2. The herein-described process which consists in subjecting porous aluminium sulfid to the action of a gaseous reducing agent at a temperature sufficient to effect the reduc tion of aluminium.

3. The herein-described process which consists in treating a porous sulfid of aluminium or porous double sulfid thereof and another metal with a hydrocarbon at a temperature sufficient to effect reduction.

4. The herein-described process which consists in treating a porous sulfid of aluminium or porous double sulfid of aluminium and another metal With a reducing agent at a temperature sufficient to effect the reduction of aluminium, then melting the resultant product with a flux.

5. The herein-described process which consists in treating a porous sulfid of aluminium or porous double sulfid of aluminium and other metal with hydrocarbon gas at a temperature sufficient to effect reduction and then melting the resultant product with a flux.

Dllll'lRI' ALEXANDROWI'IOH PENIAKOFI".

Witnesses:

GREGORY PHELAN, GEO. W. ROOSEVELT. 

